#include <bits/stdc++.h>

#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(x) (x).begin(),(x).end()

using namespace std;

int a[128];
int dp[16384];

int main() {
  int n, sum = 0;
  cin >> n;
  REP(i,n) {
    cin >> a[i];
    sum += a[i];
  }
  dp[0] = 1;
  REP(i,n)
    for (int j = 10000; j >= 0; --j)
      dp[j+a[i]] |= dp[j];
  if (sum % 2 || dp[sum/2] == 0) cout << "im";
  cout << "possible" << endl;
  return 0;
}